The number pattern below is based on a rule. Each number is somehow related to some numbers next to it. For instance, 25 and 9 could have used subtraction to come up with 16. The same simple rule is used for the entire pattern. Find the rule and solve for x.

Any given number in the bottom row (except 88) is the result of adding the suim of the digits of the number to the immediate left and the sum of digits of the number diagonally left in the top row.

For example, the number to the immediate left of 18 and the number diagonally left to 18 in the top row are respectively 16 and 38. Indeed, adding the sum of the digits of 16 and 38, we obtain: 1+6+3+8 = 18.

Accordingly, x will be obtained by adding the sum of the digits of 15 and 32. Thus, x = 1+5+3+2 = 11. This checks out, since 1+1+1+2 = 5.